Add Horizon Lock (yaw-only head tracking)#178
Conversation
Adds a "Horizon lock" toggle that flattens the head pose to yaw-only, ignoring pitch (vertical) and roll (tilt). The display then only pans horizontally as you turn your head, staying level and at a fixed height. This is a comfort/nausea aid — particularly on glasses such as the Viture Pro, where pulse and micro-movement jitter on the pitch/roll axes makes the display visibly wobble (see wheaney#80, wheaney#114). Unlike smooth follow, which chases those noisy axes, horizon lock removes them from the rendered orientation entirely. Implementation: a swing-twist decomposition about the NWU up-axis (Z), applied to the pose quaternions in DeviceDataStream, so the shader, look-ahead and follow logic all inherit the yaw-only orientation. Exposed as a GtkSwitch in the GNOME settings (Features group) and wired through the shared gschema.
|
I think actually the fix is a bit simpler than this. If I'm understanding right, it sounds like you want "smooth follow" without the "smooth." We already have "follow mode" (the "smooth" is there, but implied instead of explicitly part of the naming for Breezy), the "track axes" settings are there (you would just disable the ones you don't want, in this case only horizontal tracking would stay enabled), the only thing that's missing is a "strict follow" setting that removes the elasticity of smooth follow -- essentially disables the "slerp" part of smooth follow. So the changes here would be almost entirely in the driver, which has the added benefit of making the change available to breezy-kwin as well.
Then we only need to wire the new setting into the UI (Advanced settings) and I think that's it. |
|
Actually I bet you could get what you want with no changes, try these settings:
|
2 participants
What
Adds a Horizon lock toggle that flattens the head pose to yaw-only — the virtual display tracks only horizontal head movement and ignores pitch (looking up/down) and roll (head tilt). The screen stays level and at a fixed height; turning your head pans across it.
Why
A comfort/nausea aid. On some glasses (notably the Viture Pro) pulse and micro-movement jitter on the pitch and roll axes makes the virtual display visibly wobble — see #80 and #114. Smooth follow can't address this because it chases the noisy axes; horizon lock removes them from the rendered orientation entirely. For an ultrawide workflow you mostly look left/right anyway, so locking the vertical axis is a big comfort win.
How
applyHorizonLock()inDeviceDataStreamdoes a swing-twist decomposition about the NWU up-axis (keep the up/scalar quaternion components, zero the others, renormalize; identity fallback when yaw is undefined). Applied to both packed orientation quaternions of the pose buffer and the smooth-follow origin, so the shader, look-ahead, and follow logic all inherit the yaw-only orientation.horizon-lockgschema key + GObject property, bound inextension.js(and unbound indisable()).curved-displaytoggle.Notes
Testing
Built from source via meson; ran the extension on a Viture Pro (GNOME 50 / Wayland). With horizon lock on, looking up/down and tilting no longer move the display, while horizontal panning works as before.